Positive proportional water-meter



[No Model.)

. J. THOMSON. POSITIVE PEOPOETIONAL WATER METEE. No. 485,438. `FafuaneclNov. l, 1892.

illlllllll IH Nrrsn STATES PATENT Fries.

JOHN THOMSON, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE THOMSON HYDRAULICCOMPANY, OF NEWARK, NEW JERSEY.

POSlTlVE PROPORTINAL WATER-METER.

SPECIFICATION forming part of Letters Patent No. 485,438, dated November1, 1892.

Application filed July 1, 1892. Serial No. 438.692. (No model.)

To all whom it may concern.-

Be it known that I, JOHN THOMSON, a citizen of the United States, and aresident of Brooklyn, Kings county, New York, have invented certain newand useful Improvements in Positive Proportional Water-Meters, of whichthe following is a specification.

This is an invention in positive proportional watermeters, the generalobject of which is to nferentially indicatel a large quantity of fluidby measuring an aliquot part thereof; and the invention particularlyrelates to certain detail improvements upon my patent of May 31, 1892,No. 476,104.

The figure of the drawing is a vertical central section of theinvention. l

The component parts of the device are the measuring mechanism B,(indicated in dotted outline,) the main casing C, the valve D, the valveE, the'plunger F, and stop-nut G.

The water passes from the main inlet-chamber H in two streams, one upthrough the opening 6, then through the measuring mech* anism to theintermediate chamber I, thence through the port 7, and lnally` to themain Outlet-chamber J. The other stream passes on all sides of thevalve-casing direct to and through the ports, as 8, and thence joins therst stream in the main outlet-chamber. The several said ports arearranged in a single series radially in the valve-casing.v

In the patent herein referred to a spring is employed as a necessaryelement to the operation of the device. The spring 9 (shown in dottedoutline in the accompanying drawing) is similarly disposed; but 4thismay or may not be used, according to circumstances. The movement of thevalve toward the outletohamber is limited by the nut G, while itsmovement toward the inlet-chamber is limited by the contact of the end mof the valve against the inclosing head n of the valve-casing. Thechannel 10 and connecting-openings 11, formed in the plunger, are forthe purpose of permitting the free displacement of water to and frobetween the chamber Kback of the valve and the main outlet-chamber.

VThe operation is as follows: Under the static conditiomif the spring isemployed, the valve will be forced forward until stopped by the nut; butif the spring is not used the valve will simply remain in the positionat which it stood at the last rate of flow which passed through themeter. Presuming, however, that thevalve is at the poistion limited bythe nut or that ldenoted by the dotted lines P, the delivery will thenbe through the small forward openings of the ports, which are notcovered by the valve, and the valve may remain stationary;` but uponsufficiently increasingV the draft the several radial jets which passthrough the ports will directly impinge upon the conical face 13 of thevalve, after which the said several jets abruptly change theirdirection'of ow to a sharp right angle. The consequence of this is thatthe impact of the jets upon the inclined surface of the valve, togetherwith the reaction of the entire volume after it will have passed theports, is entirely resisted bythe valve, which when the reactive forceis sufficient will be shifted backward, uncovering the ports andcompressing the spring, if a spring is ernployed. It will now be seenthat concurrent with this action the increase of pressure of theinlet-ohamber over that of the outletchamber will act upon the end ofthe plunger and that the effect of4 any difference of pressure which mayexist between the chambers is to force the plunger and the valveattached thereto forward toward the Imain outlet-chamber. We thus havetwo opposing forces acting upon the valve-that is, the pressure of themain inlet-chamber, acting upon the head of the plunger to force thevalve toward the outlet-chamber and the direct impact and reaction ofthe discharged volume coacting to force the valve and plunger backwardtoward the inlet-chamber,which will result in moving the valve back andforth until some position of equilibrium between the opposing forceswill have been reached. In such action of the valve the water in chamberK is, as already explained, displaced through the channel formed in theplunger to the main outlet-chamber J, and vice versa when the valve isshifted forward. It ro-l mains to be here pointed out, as in theinstance of the patent cited, that the object of limiting the forwardmovement of the valve to always expose a portion of the port area is toinsure the starting of the meter, as with out this provision, should thevalve be forced forward sufficiently to entirely lap the ports, themeter would be inoperative and the ilow might be entirely stopped. Theadvantages that would accrue from employing a spring in connectionwithrthe device would be to adapt the meter to be used in any positionand to increase the difference of pressure between the working chambersat low rates of ow, as it coacts with the pressure upon the plunger,tending to force the valve forward to close the ports. The device, asdescribed, however, is perfectly and positively operative by thecombined impact and reaction of the discharge and the diiferences ofpressure between the inlet and the outlet chambers. A necessarycondition tothe operation of the device is that the area ofl the plungerwhere it is exposed to the pressureof the main inlet-chamber shall beless than that of the effective area of the valve. The object of this isthat the impact of thedischarge and the reaction thereof shall (by.acting upon a greater area than the directpressure upon the plunger)insure that the valve be driven backward for any uniform increase in therate of discharge.

The dott-ed outline let indicates that the channel l0 maybe extendedoutward beyond the immediate vicinity of `the planeof reaction, wherebythe discharged volume shall by inductive effect tend to make the chamberK negative to the main outlet-chamber J. The stud-screw l5 is to securethe valve-casing in proper relative position.

Vhat I claim is- 1. In combination, the measuring mechanism, the maincasing, the valve-casing having a series of radial ports, the valvehaving an inclined face, the plunger connected to the 4o valve, havingits.end exposed to the pressure of the main inlet-chamber, and thedisplacingchannel to connect the space back of the valve With theoutlet-chamber, substantially H as described.

